sorry if this appears a silly question...but i was thinking about buying a clevo laptop that offers the ability to put graphics cards in sli...but i am a little low on cash to be buying two GTX 780m's....I am not a super star wanna be gamer or benchmarked...but I like the latest and greatest..look at my receiver, look at my car...but anyhow...I cannot seem to find anywhere that say in a year I could buy another GPU...it appears that you have to get them with the barebones unit from manufacturer. This makes no sense, I read stories of people upgrading, but what am I missing that I don't see mobile GPU's for sale retail in my Google and Bing searches.